Abstract: Methods, devices, and systems can be used to improve accuracy and precision of stereotactic radiosurgery. For example, this document provides methods and materials for using a fiducial marker device for stereotactic radiosurgery of ocular disorders. The fiducial marker device of the invention enables positional tracking of the target tissue during the stereotactic radiosurgery procedure despite occasional movement of the eye being subjected to stereotactic radiosurgery.